This invention relates to an optical viewfinder for a film camera, video camera or the like and, in particular, to an optical viewfinder that is capable of telescoping for the viewer to select a comfortable position relative to the camera and camera support.
In the filming of high quality movies, such as for theater viewing, and the video recording of high quality productions and the like, it has become increasingly more popular to use high performance zoom lens objective systems that have been developed in recent years. Normally, the film or video camera is mounted on a support structure (a so-called camera "head") which is manually manipulated to point the camera at an object and, for example, to pan and tilt the camera as the object moves. The camera support or head has one or more handles that are either moved in the desired direction, such as on a fluid head, or rotated to cause the camera movement through gears, belts, chains or the like, and such handles are manipulated by the cameraman while viewing through a viewfinder the scene that is being photographed. For the optimum performance by and comfort of the cameraman, there should be a spacial relationship between the cameraman's eye when it is positioned at the viewfinder and the handles of the head that the cameraman must operate to cause camera movement, and that desired spacial relationship may differ from cameraman to cameraman depending on physical characteristics and personal preferences. However, the camera and objective lens must be substantially balanced on the camera head for smooth operation and to avoid inadvertent tilting, whereby the camera head is provided with a means for adjusting the fore and aft position of the camera. The objective lens system, either a fixed focal length prime lens or a zoom lens, may vary in weight from about one pound to thirty pounds which greatly affects the fore and aft balanced position of the camera on the head and yet the handle or handles of the head for causing panning and tilting of the camera remain at the same location at the base of the head, whereby the relative positions of the camera and handles varies substantially as the weight of the objective lens system varies. In turn, the relative position of the cameraman's head when his eye is positioned on the eye cup of the viewfinder and the handles that the cameraman must operate also varies substantially, which can be uncomfortable and even detract from effective operation of the camera head by the cameraman.
Heretofore, the only solution to this problem of changing relative distances between the viewfinder eye cup and the handles of the head has been to make the viewfinder in two or more different fixed lengths, called extenders, that roughly approximate good eye viewing positions for the most popular objective lens systems that require different fore and aft positions on the camera head. However, multiple detachable viewfinders are an added expense to purchase or lease, comprise additional weight and bulk for the cameraman to transport, which is a substantial problem where filming in remote locations, and their fixed lengths do not always provide the optimal eye viewing position for all zoom lenses and cameramen.